This invention relates to magnetic switches and related devices used in electrical and electronic applications, and especially to highly-reliable magnetic devices used in RF or DC circuits.
Switching devices; e.g., switches and programmable attenuators, which use electromagnetic actuating structures, typically require a number of related mechanical assemblies, including plungers, armatures, springs and rockers, to switch signals among a plurality of electrical contacts. These mechanical parts are subject to friction and resulting wear, often requiring adjustment to maintain proper alignment and interaction among key parts. Because of these characteristics, switches and related devices which rely on numerous associated mechanical parts also tend to be less reliable than their all-electronic, or solid-state, counterparts. The large quantity of mechanical parts often associated with these drivers requires labor-intensive, and, hence, costly assembly operations. In addition, these same mechanical parts tend to limit life-cycle performance. Adverse susceptibilities to temperature extremes and vibration further restrict their application and usefulness. Solid-state switches, while addressing some of these concerns, lack the power-handling and isolation characteristics of electromagnetic switches which still make them the switch of choice, in spite of all the limitations outlined above, in many applications.
With the advent of the era of personal communications, the wireless communications market demands a compact, cost-effective, reliable switching device design capable of handling both DC and RF signals without compromise of key performance parameters. Similarly, military and space applications demand switches and related devices characterized by high performance as well as high reliability, in compact, reasonably-priced packages.